Friction Force: 1.3 kg Book on 16° Plank - Find the Answer!

  • Topic:
  • Thread starter Thread starter Shah 72
  • Start date Start date
  • Tags Tags
    Friction Mechanics
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
Sign up Log in
2 replies · 2K views
Shah 72
MHB
Messages
274
Reaction score
0
A book of mass 1.3 kg is on a plank of wood which is held at 16 degree to the horizontal. The coefficient of friction between the book and the plank is 0.45.
Find the size of the frictional force.
Iam getting the ans by using the formula F= coefficient of friction ×R
5.62N but the textbook ans is 3.58N.
Pls help
 
Mathematics news on Phys.org

Discussion

using 10 for g ...

$f = \mu \cdot mg\cos{\theta} = 5.62 \, N$

an aside ... since you're using a calculator anyway, why not use 9.8 for g? g = 10 is normally used when calculations are done by hand.
 
skeeter said:
using 10 for g ...

$f = \mu \cdot mg\cos{\theta} = 5.62 \, N$

an aside ... since you're using a calculator anyway, why not use 9.8 for g? g = 10 is normally used when calculations are done by hand.
Thank you!